The present invention relates to improvements in mailing envelopes. More particularly, the invention is concerned with an improved two-way mailing envelope which, when received, can be converted into a return envelope for returning an enclosure, payment or the like.
Two-way mailing envelopes are used extensively in mail order businesses as well as in the distribution and collection of accounts. Hitherto known two-way mailing envelopes formed from single blanks comprise at least three panels folded and glued with appropriate perforated lines to provide both the first and return mailing envelopes. Examples of such envelopes are described in U.S. Pat. Nos. 3,652,007, 3,977,597 and 4,487,360.
For instance, the two-way envelope of U.S. Pat. No. 4,487,360 comprises front, rear and return panels that are joined together and folded to provide a semi-permanent fully enclosed pocket for the first mailing and a separate permanent fully enclosed pocket for the return mailing. The permanent pocket for the return mailing is formed by adhering the rear panel to the return panel. The semi-permanent pocket for the first mailing is formed by providing the front panel and one of the rear and return panels with detachable side extensions that are adhered together. Upon receipt of the envelope by the first addressee, the side extensions are removed and the front and rear panels are separated along an appropriate perforated line, thereby leaving intact the return envelope portion with its permanent pocket for return mailing. Although such a two-way mailing envelope does not require a complex manipulation for converting from its first mailing mode to its return mode, it still requires substantially the same amount of paper needed to form two separate envelopes and therefore does not allow for an economy of paper.